Telephone headsets are an important element of modern business equipment. They provide hands-free communication, and improve productivity, in a variety of applications, such as operator and information services.
One of the main applications of telephone headsets is in connection with automatic in-bound and out-bound telephone systems. Such systems generally include an Automatic Call Distributor (ACD). In a telephone system with an ACD, a computer automatically routes telephone calls to workstations connected to the system in a way that balances the call load equally between the workstations. Each workstation can be occupied by a telephone representative. For a telephone system with ACD to work properly, each telephone representative is required to log on to the system each time he/she occupies his/her workstation, and to log off the system each time he/she leaves his/her workstation. This is necessary so that the ACD will route calls to all occupied workstations, and will not route calls to any unoccupied workstations. If a representative leaves his/her workstation without logging off, the ACD system will continue to route calls to that workstation. Such calls are not responded to, or a response is delayed. A representative failing to log on to the system increases the load on the other representatives, and increases the time required to respond to incoming calls. The failure of a representative either to log on to or log off the system consequently results in a reduced quality of service.
The need for a telephone system to determine whether a workstation is occupied is not restricted to telephone systems with an ACD. For example, the sole telephone operator in a small office is also required to log off when away from his/her workstation so that incoming calls do not go unanswered.
To improve the quality of service provided by telephone systems in which the presence of a representative or operator at a workstation impacts the quality of service, it is desirable that logging on and logging off be automated.
A typical workstation includes a telephone headset connected to an amplifier. The amplifier is, in turn, connected to the workstation, which is connected to the telephone system. The amplifier is powered by current drawn from the telephone system. Automated log on/log off systems are known in which the representative has to unplug the amplifier from the workstation to log off automatically. The automatic log on/log off system monitors each workstation to determine whether or not an amplifier is connected to the workstation. The system logs the representative off when it determines that the amplifier has been disconnected from the workstation. Some types of automatic log on/log off system log the representative back on when it determines that the amplifier has been re-connected to the workstation. Other types require the representative to log back in manually.
Such automatic log on/log off systems determine whether the amplifier is connected to the workstation by monitoring some parameter that depends on whether or the amplifier is connected, such as the current drawn from the telephone system by the amplifier, or the resistance between a pair of contacts.
The log on/log off system just described is regarded as automatic, even though the representative has to connect or disconnect the amplifier, because operators prefer to continue to wear their headsets when away from their workstations, especially if the time away from the workstation is short. To be able to leave the workstation while wearing the headset, the representative has to unplug the amplifier, and has to carry the amplifier around while away from the workstation.
Recently, headset manufacturers have made it easier for a representative to leave his/her workstation while wearing his/her headset by providing a connector in the cord between the headset and the amplifier. The representative can then wear the headset while he/she is away from the workstation and no longer has to carry the amplifier. However, disconnecting the headset using the connector in the cord defeats the known automatic log in/log out systems, because the representative can leave the workstation without unplugging the amplifier, and disconnecting the headset using the connector in the cord does not change any of the parameters monitored by the known automatic log on/log off systems.
The invention provides an amplifier for connection to a telephone system. The telephone system includes a circuit for monitoring when a peripheral device, such as the amplifier, is connected to it. The monitoring circuit operates to detect a change in a parameter which occurs when the peripheral device is disconnected from the telephone system. Additionally, the amplifier is capable of establishing a communication link with a telephone headset and conveying signals between the headset and the telephone system. The amplifier includes a detecting circuit and an activating circuit. The detecting circuit detects when a communication link between the headset and the amplifier is interrupted and generates an output signal in response thereto. The activating circuit operates in response to the output signal and changes the parameter in a manner that emulates disconnecting the amplifier from the telephone system, even though the amplifier remains connected.
For example, if the monitoring circuit in the telephone system monitors an additional pair of contacts in the workstation, the activating circuit includes an additional pair of contacts. The activating circuit changes the resistance between the contacts in response to the detecting circuit's determination of when communication link between the headset and the amplifier is interrupted. If the monitoring circuit in the telephone system monitors the current drawn by the amplifier, the activating circuit changes the current drawn by the amplifier in response to the detecting circuit's determination of when the communication link between the headset and the amplifier is interrupted. Normally, the activating circuit reduces the current drawn by the amplifier when the communication link between the headset and the amplifier is interrupted.
The detecting circuit detects when a communication link exists between the headset and the amplifier by determining a change that occurs when such a link occurs. The change can be in the voltage or resistance between two conductors in a cord connecting the headset and the amplifier. For example, in one embodiment, the detecting circuit detects a change in a current drawn from the amplifier by the headset. Alternatively, the change can also be in the strength of a signal communicated between the headset and the amplifier. For example, in one embodiment, the detecting circuit detects a change in the level of an ac voltage transmitted between the headset and the amplifier.
The monitoring circuit in the telephone system may additionally operate to detect a change in the parameter which occurs when the peripheral device is reconnected to the telephone system. In this case, the detecting circuit may additionally detect when the communication link between the headset and the amplifier is reestablished and may generate an additional output signal in response thereto. The activating circuit may then additionally operate in response to the additional output signal to change the parameter in a manner that emulates reconnecting the amplifier to the telephone system, even though the amplifier has not been disconnected.
The invention also provides a method of activating an automatic monitoring circuit in a telephone system in response to an interruption in a communication link between a headset and an amplifier connected to the telephone system. The automatic monitoring circuit monitors when a peripheral device, such as the amplifier, is connected to the telephone system by detecting a change in a parameter which occurs when the peripheral device is disconnected from the telephone system. The method includes: the steps of detecting when a communication link between the headset and the amplifier is interrupted, and generating an output signal in response thereto; and changing the parameter in response to the output signal in a manner to emulate disconnecting the amplifier from the telephone system, even though the amplifier remains connected.